EPA okays pesticide exemption requests

In a flurry of recent activity, the Environmental Protection Agency has granted several requests by Mid-South states for emergency use labels for various pesticides.

Among the Section 18 exemptions issued by EPA in 2001 are products to control aphids in cotton, red morningglory in sugarcane, blue-green algae in catfish ponds and bermudagrass in sugarcane.

Cotton growers in Mississippi are also awaiting word on Section 18 requests for permission to use Centric (thiamethoxam)and Assail (acetamiprid) for the control of aphids and whiteflies, and Denim (emamectin benzoate) for the control of beet armyworms and resistant tobacco budworms.

A roundup of the recent label requests and approvals or denials is as follows.

Furadan

A Section 18 emergency exemption has been granted by EPA for Mississippi cotton growers to use Furadan 4F (carbofuran) to control aphids, according to Tommy McDaniel, director of the Mississippi Bureau of Plant Industry in Jackson, Miss. The request was approved by EPA March 30.

“Farmers must have the means to adequately control aphid populations,” says Mississippi Agricultural Commissioner Lester Spell, who says, the emergency exemption request was made in order to prevent an adverse economic impact to the cotton farmer.

Furadan 4F is manufactured by FMC Corporation. It is not registered for use on aphids in cotton.

According to the EPA, personnel from the Mississippi State University Extension Service will be monitoring cotton fields this summer to check the levels of aphid populations. The exemption for Furadan will be triggered when aphid numbers exceed the threshold level.

Once county Extension agents have certified that conditions in his or her region have reached an “emergency level,” growers may then, under specific application guidelines set by EPA, apply Furadan 4F, by ground or air.

The treatment rate of Furadan 4F specified by the Section 18 exemption is 8 ounces of product per acre or 0.25 pound active ingredient per acre. A maximum of two treatments may be made, but growers may not apply more than 0.5 pounds active ingredient total per acre.

Spartan 75DF

The Environmental Protection Agency has approved an emergency exemption request for the herbicide Spartan 75DF to be used in Louisiana for the control of red morningglory in sugarcane.

Depending on soil texture and organic matter content, Spartan 75DF should be applied at a rate range of 6.7- to 8-ounces per acre, according to its manufacturer, FMC Corporation.

“The Spartan exemption is in response to widespread infestation of red morningglory in Louisiana sugarcane. According to university and FMC data, Spartan provides control of morningglory, especially red morningglory, that is greater than that of currently registered products,” says Mike Steffack, FMC North America marketing manager. “Spartan can be applied in the spring, at lay-by or in the fall for plant-cane.”

Command 3ME

Under a crisis exemption, the EPA has given Louisiana sugarcane growers permission to use the herbicide Command 3ME for the control of bermudagrass.

“Realistically, sugarcane growers will have the most success using a program approach for bermudagrass control,” says Brenda Franke, Command product manager for FMC. “Research shows that a combination of Command and Diuron is one of the best ways to tackle a touch bermudagrass problem.”

According to its Section 18 supplemental label, Command 3ME should be used at a rate of 2 2/3- to 3 1/3-pints per acre. The herbicide has been approved for ground application only.

Diuron

The Environmental Protection Agency has granted its permission for catfish farmers in Mississippi and Arkansas to use the chemical, diuron, for the control of blue-green algae. The algae, when present in catfish ponds, is linked to off-flavor catfish, a major problem in catfish production.

The emergency use permits, which were requested Jan. 23 by Mississippi officials and Feb. 6 by Arkansas officials, were approved March 8.

Denim

Although a request for an emergency exemption use permit for Denim was made early in the year in order to obtain approval in time to benefit those cotton producers battling high populations of the insects this summer, EPA has still not responded.

State officials in Mississippi and Texas are asking for permission to use Denim (emamectin benzoate) for the control of beet armyworms and resistant tobacco budworms in cotton. If the request is approved, other Southern states could follow their neighbors' lead.

The reason for Mississippi's exemption request, McDaniel says, is that beet armyworm outbreaks have caused serious yield losses in past years and that involvement in the boll weevil eradication effort increases the risk of serious outbreaks occurring. Researchers have also detected insecticide resistant tobacco budworm populations in the state.

A severe outbreak of beet armyworms would, according to the state's exemption application, result in the treatment of at least 750,000 cotton acres statewide. In the event of an outbreak of resistant tobacco budworms, McDaniel estimates that a minimum of 400,000 acres of non-Bt cotton could require treatment.

Centric and Assail

An April 5 request by the Mississippi Bureau of Plant Industry for the use of the products, Centric (thiamethoxam) and Assail (acetamiprid), for the control of cotton aphids and whiteflies in cotton is still awaiting action by EPA.

According to Tommy McDaniel, branch director of the Mississippi Department of Agriculture and Commerce's Bureau of Plant Industry, consistent control of aphids has become very difficult to achieve in recent years with currently available materials due to high levels of insecticide resistance.

In addition, he says, “The potential for a serious whitefly outbreak to occur this year is significant. Whitefly populations are often flared by boll weevil eradication efforts and this year, all of Mississippi will be involved in the boll weevil eradication program. The ability to use Centric and Assail for use on whiteflies would make growers able to control this pest.”